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Commit 83ee87a3 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

V4L/DVB (8026): Avoids an OOPS if dev struct can't be successfully recovered 

On some alsa versions, it seems that snd_pcm_substream_chip(substream)
is returning a NULL pointer. This causes an OOPS, as reported by:

https://bugs.launchpad.net/ubuntu/+source/linux-ubuntu-modules-2.6.24/+bug/212271
https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/212960



This patch avoids the OOPS by not letting and open() succeed.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@infradead.org>
parent 913f5fc2

drivers/media/video/cx88/cx88-alsa.c

+6 −0
Original line number Diff line number Diff line
@@ -332,6 +332,12 @@ static int snd_cx88_pcm_open(struct snd_pcm_substream *substream) 
	struct snd_pcm_runtime *runtime = substream->runtime;

	int err;



	if (!chip) {

		printk(KERN_ERR "BUG: cx88 can't find device struct."

				" Can't proceed with open\n");

		return -ENODEV;

	}



	err = snd_pcm_hw_constraint_pow2(runtime, 0, SNDRV_PCM_HW_PARAM_PERIODS);

	if (err < 0)

		goto _error;

drivers/media/video/em28xx/em28xx-audio.c

+6 −0
Original line number Diff line number Diff line
@@ -268,6 +268,12 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream) 


	dprintk("opening device and trying to acquire exclusive lock\n");



	if (!dev) {

		printk(KERN_ERR "BUG: em28xx can't find device struct."

				" Can't proceed with open\n");

		return -ENODEV;

	}



	/* Sets volume, mute, etc */



	dev->mute = 0;

drivers/media/video/saa7134/saa7134-alsa.c

+7 −1
Original line number Diff line number Diff line
@@ -613,9 +613,15 @@ static int snd_card_saa7134_capture_open(struct snd_pcm_substream * substream) 
	struct snd_pcm_runtime *runtime = substream->runtime;

	snd_card_saa7134_pcm_t *pcm;

	snd_card_saa7134_t *saa7134 = snd_pcm_substream_chip(substream);

	struct saa7134_dev *dev = saa7134->dev;

	struct saa7134_dev *dev;

	int amux, err;



	if (!saa7134) {

		printk(KERN_ERR "BUG: saa7134 can't find device struct."

				" Can't proceed with open\n");

		return -ENODEV;

	}

	dev = saa7134->dev;

	mutex_lock(&dev->dmasound.lock);



	dev->dmasound.read_count  = 0;